A free concert at a shopping mall in Denmark descended into violence on Wednesday when fans began rioting as police evacuated the venue due to a fire alarm alert. Akon put on the free gig at Fields Shopping Mall in Copenhagen.

Mall director Jens Geppel says, “It was a free concert and we knew that many people would come, but there were a lot of people there, more than we had expected.”

A fire alarm was set off, prompting to evacuate the building, that’s when all hell broke loose. Concert-goers started throwing rocks and drinks bottles at the officers, resulting several people were injured in the incident.